A rubber track for vehicles

Abstract: The rubber vehicle track comprises a rubber structure (1) exhibiting on an external surface a series of shaped reliefs (2) and on an internal surface a series of metal elements (3) partially sunk into the rubber structure (1), projecting from said structure (1) and aligned one to another in at least one line to form a rigid rolling surface as rail tracts (4), for vehicle rollers. Each rail tract (4) exhibits a longitudinal extension (6), made in rubber or in another elastic material, forming a single body with and being taller than the rail tract (4), and having a convex top surface. The rubber extension (6) is separated from a contiguous rail tract (4) by a recess (7) cut perpendicular to a lie plane of the internal surface of the rubber structure (1).

Description: The invention relates to a rubber track for vehicles. The track is especially applicable to excavators, combine harvesters and all vehicles which operate off-road but also need to be able to move on asphalted surfaces The rubber used for the track prevents damage to an asphalted road surface, as well as being much quieter than metal tracks. Known-type rubber tracks exhibit longitudinally-aligned vertically-projecting metal rail track sections on an inside surface of the tracks, and partially sunk into the rubber, which the vehicle-bearing wheels run on. The rail track sections are distanced longitudinally such that when the track winds around the vehicle drive wheels the rail track sections do not interfere one with another. This leads to a considerable drawback: when the vehicle-bearing wheels run on the rails, the spaces between track sections cause movement irregularities when the vehicle is translated, which are transmitted to the vehicle itself in the form of jumps and starts arid small but constant vibrations. To obviate this drawback, many track manufacturers have in some way done away with the spaces between the rail track sections, creating what is in effect a constant rolling plane for the vehicle rollers. Japanese Patent Application JP-A- 4002583 The Ohtsu Tire and Rubber Co. LTD is structurally the closest in type to the present invention. The rubber track exhibits aligned metal rails wherein situated between one and a next rail section is a rubber block, which is taller than the rails. When a roller runs off one metal rail track section it comes into contact with the top of the rubber block, compressing it so that it fills the space between the two rails. Thus the running plane of the rollers is constant and continuous and the above-mentioned vibrations are to some extent obviated. This system undoubtedly functions well, but presents some drawbacks, especially in that the 25 rubber block is completely independent of the rail track sections and therefore behaves like an isolated and independent cylinder, and also in that it is subject to continuous compressions by the vehicle and is thus exceptionally susceptible to fast wear and breakage at its base. A further drawback is that the independence of the rubber block does not fully guarantee rolling continuity from rail track section to rubber block and vice versa. The above invention also suffers from accumulations of stones, mud and such inert materials picked up from the work environment, which the vehicle picks up in the interspaces between the rubber blocks and the metal rail track sections. The principal aim of the present invention is to overcome the above-described drawbacks by providing a rubber track enabling the vehicle to translate normally, without vibrations due to discontinuity problems between rail track section, and which also enables inert materials to be eliminated instead of accumulating on the running planes of the rollers. These and other aims are all attained by the rubber track of the invention as defined in Claim 1. Further characteristics and advantages of the present invention will better emerge from the detailed description and dependent claims that follows, of a preferred but non-exclusive embodiment here illustrated in the form of a non-limiting example in the accompanying drawings, in which: figure 1 shows a portion of the track of the invention, in a plan view from the internal side of the track; figure 2 shows a view of the section along line II-II of figure 1; figures 3 and 4 respectively show in plan view and perspective view one of the numerous metal elements which are sunk into the rubber of the track; figure 5 shows a perspective view of the rubber portion of figure 1; figures from 6 to 10 show the same views as figures from 1 to 5, regarding a second embodiment of the invention; figures from 11 to 15 show the same views as figures from 1 to 5, regarding a third embodiment of the invention; figures from 16 to 20 show the same views as figures from 1 to 5, regarding a fourth embodiment of the invention. With reference to the figures of the drawings, 1 denotes a portion of a rubber structure constituting a vehicle track. On its surface facing the road surface it exhibits a series of shaped reliefs 2, while on its surface facing the vehicle rollers it exhibits a series of metal elements 3 partially sunk into the rubber structure 1. The part of the metal elements 3 projecting perpendicularly from the rubber structure 1 forms a rail track section 4: several of the metal elements 3 are aligned longitudinally along the track to form a rigid rolling plane for vehicle rollers (not illustrated). In the embodiments shown in figures from 1 to 10, the rail track sections 4 are situated in two parallel lines, while in the embodiments of figures 11 to 20, two further parallel lines of rail track sections 5 are situated by the sides of the first pair of rail track sections 4, and are shorter in height than them. The third and fourth embodiments are designed to support rollers of different heights, though all of known type. Each of the rail track sections 4 (or 5) longitudinally exhibits a rubber (or other elastic material) extension 6 which forms a single body with the rail track section and which is taller than it (measuring from the rubber track internal surface lie plane). The rubber extension 6 has a convex top surface (see figures 5, 10, 15, 20). Each of the rubber extensions 6 is separated from a successive rail track section by a recess 7 cut perpendicular to the surface of the rubber structure 1. Each recess 7 receives a part of the rubber extension 6 which is deformed when compressed by a roller passing over it, so that a continuous rolling plane is created. Furthermore, at the point where the rail track sections 4 project from the rubber surface, each recess 7 extends transversally, cutting into the rubber structure 1. This recess extension (denoted in figures 5, 10, 15 and 20 by number 8), affords the rail track sections 4 space in which to bend back when they meet the drive cogwheel or the endwheel. The rubber extensions 6 are also provided with a swelling 9 to strengthen their bases. In a position corresponding to the swellings 9, each recess 8 exhibits a cavity 10 to receive a swelling 9 when the rubber extension 6 is elastically deformed due to the action of the rollers. In figures 6, 10, 16 and 20, the rubber extensions 6 have a dead hole 11 bored into them, having a perpendicular axis to the lie plane of the rubber structure 1. The dead hole 11 enhances the deformability of the rubber extensions 6. Also worthy of note is that each rail track section 4 top surface has recesses 12 cut into it to improve drainage of inert materials, such as grit and mud.

Claims: A rubber track for vehicles, comprising a rubber structure (1) exhibiting on an external road-facing surface a series of shaped reliefs and on a vehicle-roller-facing internal surface a series of metal elements (3), partially sunk into the rubber structure and projecting from the internal surface of said rubber structure forming rail track sections (4); said metal elements (3) being set in an aligned sequence along and forming at least one complete line along the internal surface of the rubber structure, and providing at least one rigid plane for rollers of the vehicle to run on, characterised in that the part of the metal elements, projecting from said internal surface in each rail track section (4), longitudinally exhibits a rubber extension (6), which is made either in a same or a different elastic material as the rubber structure, forming a single piece with the rail track section (4) and projecting higher than said part of the metal elements (3) projecting from said internal surface, and having in the longitudinal direction a convex top surface; each said rubber extension (6) being separated from a contiguous rail track section (4) by a recess (7) cut perpendicularly to the plane of the rubber structure (1). A rubber vehicle track as in claim 1, characterised in that the recess (7) exhibits a recess extension (8) extending into the rubber structure (1) transversally to a line formed by a succession of rail track sections (4). A rubber vehicle track as in claim 1, characterised in that each said rubber extension (6) exhibits a rubber swelling (9) arranged laterally at a position where said rubber extension (6) meets said plane of the rubber structure (1). A rubber vehicle track as in claims 2 and 3, characterised in that the rubber extension (6) exhibits a recess extension (8) affording a cavity (10) situated in proximity of the rubber swelling (9). A rubber vehicle track as in claim 1, characterised in that each said rubber extension (6) exhibits a dead hole (11) bored into a top surface of the rubber extension (6), said dead hole (11) having an axis which is perpendicular to the plane of the rubber structure (1). A rubber vehicle track as in claim 1, characterised in that each said rail track section (4) has a top surface exhibiting shaped recesses (12).

Inventors: MAI RENATO, MAI, RENATO
Applicants: MAI SPA, MAI S.P.A.
Application year: 1994
Main classification: B62D55
IPC codes: B62D55